Walk-athon To Raise Funds For Children Helping Children Program By NANCY LASTRINA; Courant Columnist Nancy Lastrina, an Enfield native, collects news about residents of north central Connecticut for this column, which appears on Tuesdays and Fridays. Please send contributions to her at The Courant, 101 Phoenix Ave., Enfield, CT 06082. The phone number is 253-5722 and the fax number is 741-7174.Courant correspondent Sherman Tarr contributed to this column.